The invention relates to printed articles that display images, which may include composite images. The printed articles may include secure credit cards, trading cards, greeting cards, signs, posters, labels, decals, book covers, decorative panels, name plates, visual displays and the like. The printed articles may display or project a composite image magnified by a plurality of clear geometric lenses printed or formed above a patterned graphic design. The composite image may embody visual illusions of depth, three-dimensionality, hidden images or motion. The composite image may provide the printed article with identifiable features which cannot be easily copied (e.g., holographic images, hidden images, and the like).
In order to attract the attention of consumers, many products are manufactured with images that provide a unique and sensational visual presentation. To meet this demand, a variety of printing techniques have been developed to produce aesthetically pleasing visual effects, such as the appearance of depth, three-dimensionality and motion. In addition, various methods are known in the prior art that produce hidden or latent images or three-dimensional images on two-dimensional media. The hidden or latent image may become apparent only upon viewing the two-dimensional media from an angle.
In addition, the use of hidden or latent images or three dimensional images may be useful to prevent counterfeiting, where the images cannot be copies by conventional methods. The only way to duplicate the appearance and floating or hidden image effect is to recreate the actual printed article, including the embodied graphical and optical layers.
One method for creating three-dimensional images involves printing two offset images in different colors on an opaque or transparent sheet, and viewing the images using special glasses having right and left lenses which correspond to the different image colors respectively. This method is limited in that to see the visual effect the viewer must observe the image typically through special glasses.
Another method to achieve a three-dimensional or animated visual presentation is through the use of a lenticular or lens-array imaging systems. In these systems, an array of parallel convex lenses is formed over a clear plastic substrate, where the parallel lenses magnify portions of images printed under them. By viewing the substrate from different angles, a view observes different focused portions of the underlying images such that an overall image or pattern is seen at one viewing angle and a different image is visible at another viewing angle. This can result in a number of visible effects such as a three-dimensional image, a simple image A to image B flip (or transversion), or multiple images that show a series of images from one viewing angle to another resulting in the appearance of viewing a motion video clip. Despite the variety of possible effects, these systems have had limited success because manufacturing expenses and material costs are very high. Systems of the prior art also are limited in that they may utilize a prefabricated sheet of lenses, rather than lenses that are directly printed on a selected portion of a graphic image.
U.S. Pat. Nos. 6,856,462 and 6,833,960 describe lenticular imaging systems (hereinafter referred to as the '462 and '960 patents, respectively). Both the '462 and '960 patent describe printing or forming an array of lenses comprising a plurality of linear or circular shapes when viewed from a top planar perspective. However, the lenticular systems disclosed in the '462 and '960 patent are limited in that they use linear or circular shaped lens. The clarity of a composite image produced from an array will be proportional to the amount of magnifying lens material in the array versus non-magnifying space between the magnifying lens material. Therefore, it is desirable that the lenses within an array are packed as closely as possible. The permitted proximity of the lenses, however, will be limited because of “flooding” which may occur after a lens array is printed and prior to curing. “Flooding” occurs when the surface tension of the printed lenses is not sufficient to prevent a lens from merging with one or more adjacent lenses prior to curing. “Flooding” destroys the uniformity of an array. Accordingly, lenses must be positioned in an array to include a space between adjacent lenses to avoid flooding. The geometry and positioning of the lenses in the disclosed articles should be selected to maximize the percent area of magnifying lenses and minimize non-magnifying areas within a plurality of lenses in view of this space between lenses.
In addition, it is desirable to maximize the height (or thickness) of lenses in an array in order to maximize magnification. The permitted height of the lenses also will be limited because of “flooding” where the surface tension of the liquid used to form the lenses will not permit lenses of excessive height without flooding occurring. Therefore, the geometry and positioning of the lenses in the disclosed articles also should be selected to maximize the permitted height of the lenses.
Linear and circular shaped lenses do not achieve these stated goals. Linear lenses have limited use in lenticular systems because they focus only in a linear direction and present additional difficulties with respect to obtaining desirable lens height. Circular shaped lenses are disadvantageous in that their curved shape does not permit the closest possible packing arrangement within a lens array further in view of avoiding “flooding.”
U.S. Pat. No. 5,800,907 discloses a lens body or article with lenses that is produced by forming “lens-forming defining lines” on the surface of a substrate. The “lens-forming defining lines” are used to create a patterned grid on the surface of a substrate and a lens-forming resin then is applied to the patterned grid. The lens-forming resin is insoluble in the material used to create the “lens-forming defining lines” and forms lenses within the spaces of the patterned grid after the patterned grid is coated with the lens-forming resin. As such, the '907 patent does not disclose that lenses can be directly applied or printed on an image (or micropattern image) on a surface of the substrate. Furthermore, the “lens-forming defining lines” of the '907 patent add complexity and cost to methods of manufacturing the disclosed articles.
The present invention achieves these goals and overcomes these limitations in the prior art by utilizing transparent polygonal lenses that are applied or printed on an image (or micropattern image) on the surface of the substrate. Printed articles and lenticular imaging utilizing the transparent polygonal lenses display images having improved definition and depth.
Reference to any prior art in the specification is not, and should not be taken as, an acknowledgement or any form of suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person of ordinary skill in the art.